“All New” Glass Fun Facts: Part 2

The WGS Blog returns to provide More.  Glass.  Trivia!

As far as the early history of glass making in Britain goes, the Romans brought the technology with them. This led to the European-wide spread of glass manufacture. British history records glass “Manufacture” dating back to the 13th century when “Broad Sheet” glass can be located to the areas around Sussex and Surrey. In the meantime the Venetians had thrived as glassmakers, as their glass became popular due to its brilliance and creative form. By 1330 the French had also developed “Crown Glass”. This took until the 17th century to be produced in England, in London.

 In England in 1676 George Ravenscroft invented “Lead crystal” by introducing lead oxide to the glass which took on a more brilliant appearance.

 The 17th century brought a new glass process from France, “Plate glass”, a term still used today. This was a process of pouring molten glass onto a table and then rolled. Once cold, the glass was ground under large grinding disks until optically smooth, making it perfect for mirrors. The French had legislated heavy duties on imported glass products which made it impossible for the Venetians to Export, and also offered generous incentives to any Venetian willing to work for them. By the 18th century this technology was being used in England at Ravenhead, producing the first English Polished Plate.

Crystal-Palace-general-view1

The Crystal Palace was a cast-iron and plate-glass building originally erected in Hyde Park, London, England, to house the Great Exhibition of 1851

1834, Robert Lucas Chance introduced “Improved Cylinder Sheet” glass which was produced using a process invented in Germany. This produced even finer and larger glasses. This was the glass used to glaze the “Crystal Palace” in London. Until a change in legislation in 1845 when the “Excise Act” was repealed, glass manufacture was under developed in Britain. Once the heavy tax burdens previously placed on glass manufacture were removed, production grew.

By the end of the 19th century glass bottles were being made by machine, increasing production threefold. The now “Chance Bros.” invented “Machine Rolled Patterned Glass”. By the start of the 20th century, “Owens Glass” in America had further developed bottle manufacture which increased output by 10-fold to some 2,500 bottles per hour.

bottle.make

By 1910 the first “Laminates” had been produced by Edouard Benedictus, a Frenchman, who named the process “TripleX.” 1914 saw the start of producing glass by the “Drawn” method. Invented by a Belgian man named Fourcault, glass was drawn vertically from a tank. A further development by Richeroux, another Belgian, was to pour the molted glass from a pot between 2 rollers to give a more even thickness and evenness for polishing.

In 1917 “Sheet Glass” was invented by Colburn in America and developed by “Libby-Owens”, a partnership of Michael Owens of Owens glass and his backer E. D. L. Libby. Further improvements were made by “Pittsburg Plate Glass” or PPG.

By 1923 came the first UK production of continuous polished plate glass using the single grinding system. Closely followed in 1938 by the twin grinding system. And then the float process was launched in the marketplace; invented by Pilkington Bros, and introduced in 1959. The significance of this process is that it produced glass with a brilliant finish and without the need to grind or polish the surface, making mass-produced glass with the qualities of polished glass. This was achieved by floating the molten glass on a bath of molten tin, creating a “glass ribbon”, even in width and thickness. This is still the process used today for the production of what is now termed “Float Glass”. 

Glass is commonly used for windows, bottles, modern hard drives and eyewear, and examples of glassy materials include soda-lime glass, borosilicate glass, acrylic glass, sugar glass, Muscovy-glass, and aluminium oxynitride.

Much of the functional architectural glass – like that used in shower doors, table tops, car windows, skylights, etc. – goes through a process called tempering.  Glass is pretty wonderful stuff, but it does have some bad habits.  First, it is brittle and has a tendency to crack when struck or heated unevenly.  Second, shards of glass are really sharp and pretty dangerous.  Tempered glass solves both of these problems simultaneously.  Glass is much stronger in compression than tension.tempered.glass

Tempered Glass Process

If you can cause the surface of the glass to become compressed relative to the interior of it, you can harden it by a factor of up to 10.  There are a couple of ways to do this.  One is to heat the glass and then cool it very quickly.  The surface of the glass will cool much more rapidly than the interior.  The slow cooling of the interior causes it to want to contract more than the surface, placing the surface under considerable compression.   This strengthens the glass and makes it more scratch-resistant and heat-resistant in the bargain.  Another method is chemical tempering, in which sodium atoms on the surface of the glass are replaced with potassium atoms, which are significantly larger.  This also puts the surface in compression, and can be done with glass of complicated shapes that would not survive heat tempering.

One interesting effect of the tempering process is that tempered glass doesn’t just crack.  When tempered glass encounters a big enough stress, it shatters into small granules.  If the integrity of the surface of the glass becomes compromised, the interior, which is under huge tension, will disintegrate.  This is much safer than big dangerous shards, but does make the glass suddenly an awful lot harder to see through.  This is one reason why the windshield of your car is not made with tempered glass, but laminated glass.  Laminated glass is made by bonding two or more layers of glass with an ‘interlayer’ of plastic film which will hold the pieces together if the glass should crack.

willis-tower-ledge-shatter

Chicago’s Willis (aka Sears) Tower 103rd floor Skydeck had one of its famous glass ledges shatter an interlayer May 2014

Tempered glass is an extremely useful material, but it does demand some planning.  Because of tempered glass’ all-or-nothing breakage, it must have been already cut to the size, shape, and already have any holes cut out before the tempering process.  There’s no cutting the glass down to fit afterwards. replace.sears.willis.tower.glass.ledge

Tempering as an industrial process started in the 20th century, but it was a party trick far before that.  One of the first examples of tempered glass is something called Prince Rupert’s drops (or balls) , named after the Bavarian prince who brought it to the attention of the court.  If you let a blob of molten glass drip into a bucket of water, it will form an extended teardrop shape with interesting properties.  The bulbous end of the drop is tempered and can withstand extreme force, such as hitting it with a hammer.  The tail, however, is very delicate, and if broken, the whole thing will shatter into tiny pieces. 

When you think about it the stuff is a bit odd, but that’s glass for you.  It’s odd stuff.

Click HERE to jump to Part 1

“All New” Glass Fun Facts: Part 1

Its been a while since we got our glass geek on. These fact-filled glass trivia were very popular when we were on the old blog format, and we’re ready to burst with glass bits-of-info.

When glass breaks, the cracks move at speeds of up to 3,000 miles per hour.

breaking-glass-oThin-glass goblets can vibrate when hit by sound waves. This is due to resonance.

Glass takes over 1 million years to decompose in our landfills and dumps. Recycling glass reduces air pollution by 20%, and water pollution by 50%. Only 27% of the glass used in the United States is recycled. A typical glass recycling factory can recycle up to 20 tons of glass per hour. The energy saved from recycling 1 glass bottle can run a 100-watt bulb for 4 hours.

glass landfillHydrofluoric acid will dissolve glass.

From the start of time glass has been available to man. Stone Age man used obsidian (a naturally formed glass) for cutting tools and weapons. The Phoenicians also accidentally discovered glass when cooking near nitrates that when heated formed glass. However, we have to wait until the Egyptian times before we can actually trace deliberate glass manufacture which was in the form of beads.

core-forming_glass

In 1500 BC, we believe the first glass bottles were made using the “Core-Forming Method”.

early.venetian.glass

The term glass developed in the late Roman Empire. It was in the Roman glassmaking center at Trier, now in modern Germany, that the late-Latin term glesum originated, probably from a Germanic word for a transparent, lustrous substance.Glass manufacture had developed in Venice by the time of the Crusades (A.D. 1096-1270), and by the 1290’s an elaborate guild system of glass workers had been set up. 

Later this week: Part 2 All New Glass Fun Facts!

Click HERE to jump to Part 2

Newly Found Blue Planet Where It’s Raining Glass! Hallelujah!

Interstellar Glass Fun Facts 
Astronomers said they had found another blue planet a long, long way from Earth — no water world, but a scorching, hostile place where it rains glass, sideways.

Blue planet HD 189733b around its host star (artist’s impression)

Using the Hubble Space Telescope, scientists from NASA and its European counterpart, ESA, have for the first time determined the true color of an exoplanet, celestial bodies which orbit stars other than our own Sun. 
They concluded that HD 189733b, a gas giant 63 light-years from Earth in the constellation Vulpecula (the Fox), was a deep cobalt blue, “reminiscent of Earth’s color as seen from space.”
“But that’s where the similarities end,” said a statement. This planet orbits very close to its host star and its atmosphere is heated to over 1,800 degrees Fahrenheit.It rains glass, sideways, in howling 4,350 miles-per-hour winds,” said the statement. The planet is one of the nearest exoplanets to Earth that can be seen crossing the face of its star, and has been intensively studied by Hubble and other telescopes.

“Measuring its color is a real first — we can actually imagine what this planet would look like if we were able to look at it directly,” said Frederic Pont of the University of Exeter, who co-wrote the paper in Astrophysical Journal Letters. Pont and a team measured how much light was reflected off the planet’s surface, a property known as albedo, in order to calculate its color. 

HD 189733b was discovered in 2005. It is only 2.9 million miles from its parent star, so close that it is gravitationally locked. One side always faces the star and the other side is always dark.In 2007, NASA’s Spitzer Space Telescope measured the infrared light, or heat, from the planet, leading to one of the first temperature maps for an exoplanet. The map shows day side and night side temperatures on HD 189733b differ by about 500 degrees Fahrenheit. This should cause fierce winds to roar from the day side to the night side.

With apologies to the Weathergirls & writers of Its Raining Men: 

Barometer’s getting low

According to all sources,the street’s the place to go

Cause tonight for the first time

Its gonna be badass 

For the first time in history

It’s gonna start raining glass.

Its Raining Glass! Hallelujah! 

Other WGS : Glass Fun Facts

Glass Fun Fact: Prince Rupert’s Drops and Tempered Glass

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Much of functional architectural glass applications – like shower doors, table tops, car windows, skylights, etc. – requires the use of safety glass - often glass that has through a process called tempering.  Glass is pretty wonderful stuff, but it does have some bad habits.  First, it is brittle and has a tendency to crack when struck or heated unevenly.  Second, shards of glass are really sharp and pretty dangerous.  Tempered glass solves both of these problems simultaneously.  Glass is much stronger in compression than tension.

Float Glass process

If you can cause the surface of the glass to become compressed relative to the interior of it, you can harden it by a factor of up to 10.  There are a couple of ways to do this.  One is to heat the glass and then cool it very quickly.  The surface of the glass will cool much more rapidly than the interior.  The slow cooling of the interior causes it to want to contract more than the surface, placing the surface under considerable compression.   This strengthens the glass and makes it more scratch-resistant and heat-resistant in the bargain.  Another method is chemical tempering, in which sodium atoms on the surface of the glass are replaced with potassium atoms, which are significantly larger.  This also puts the surface in compression, and can be done with glass of complicated shapes that would not survive heat tempering.

One interesting effect of the tempering process is that tempered glass doesn’t just crack.  When tempered glass encounters a big enough stress, it shatters into small granules.  If the integrity of the surface of the glass becomes compromised, the interior, which is under huge tension, will disintegrate.  This is much safer than big dangerous shards, but does make the glass suddenly an awful lot harder to see through.  This is one reason why the windshield of your car is not made with tempered glass, but laminated glass.  Laminated glass is made by bonding two or more layers of glass with an ‘interlayer’ of plastic film which will hold the pieces together if the glass should crack.

Tempered glass is an extremely useful material, but it does demand some planning.  Because of tempered glass’ all-or-nothing breakage, it must have been already cut to the size, shape, and already have any holes cut out before the tempering process.  There’s no cutting the glass down to fit afterwards. 

Tempering as an industrial process started in the 20th century, but it was a party trick far before that.  One of the first examples of tempered glass is something called Prince Rupert’s drops (or balls), supposedly named after the Bavarian prince who brought it to the attention of the Royal Society.  If you let a blob of molten glass drip into a bucket of water, it will form an extended teardrop shape with interesting properties.  The bulbous end of the drop is tempered and can withstand extreme force, such as hitting it with a hammer.  The tail, however, is very delicate, and if broken, the whole thing will shatter into tiny pieces.  

When you think about it the stuff is a bit odd, but that’s glass for you.  It’s odd stuff.

A local DC morning news television station visited Erwin Timmers’ recycled glass art class, and he demonstrated the explosive properties of tempered glass by shattering a thick panel (jump to 2:47).
Click on each line below to jump to previous Glass Fun Facts postings:
Glass Fun Facts: Gaffer/Composer
More Glass Fun Facts: Bullseye Glass

Float Glass Fun Facts
Glass Fun Facts – Shattered Glass Predicts Weather
Why is Glass Transparent?

Yet Even MORE Glass Fun Facts! Mars Is Filled With Glass!

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C’mon Wall-e

Dark patches visible across much of the northern Martian hemisphere aren’t canals or vegetation, as once thought, but glasscreated by volcanic action according to a new study. The discovery by Briony Horgan and James Bell from Arizona State University, provides evidence of the same sort of processes seen on Earth, also happening on the Red Planet.

Dark areas are thought to be volcanic glass.
Credit: NASA/University of Arizona. 

Using near infrared spectroscopic data collected by the European Space Agency’s Mars Express orbiter, Horgan and Bell found widespread weathered volcanic glass covering the surface of the Martian lowlands.

“The volcanic glass was created when hot magma reacted explosively with ice or water,” says Horgan. “The same sort of thing happens in Iceland, where volcanoes erupt under glaciers. The interaction with the ice and the water causes the magma to become super-explosive, creating tons of sand sized black particles…”We see these dark plains and enormous glassy sand dune fields up in the northern Martian polar regions”

Horgan and Bell also found evidence of dips in the spectrum consistent with weathering caused by the glass being exposed to acidic water.

Their finding, which appear in the journal Geology, represents the first detection of widespread surface weathering during the Amazonian epoch — the most recent of the three Martian geologic periods. Click HERE to read about it in the Huffington Post

Mars may have glass, but what it needs is a more feminine touch.

Click on each line below to jump to previous Glass Fun Facts postings:
Glass Fun Facts: Gaffer/Composer
More Glass Fun Facts: Bullseye GlassFloat Glass Fun FactsGlass Fun Facts – Shattered Glass Predicts Weather
Why is Glass Transparent?

Historical Glass Fun Facts – How the Invention of Pyrex and The Studio Glass Movement are Connected.

Mondo Bizzaro Glass – Yet Still More Glass Fun Facts

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mmm…glass

The normally august and sane National Geographic channel treats us to a freak show, titled Humanly Impossible, with one segment all about a glass eater. The series offers a look into extreme performers such as glass eaters and sword swallowers that push the human body to extraordinary limits. But how do they do it? Humanly Impossible follows a team of doctors and scientists to reveal the physiology behind bizarre and dangerous stunts that surpass average human capability.

Artist’s rendering of an inside-the-mouth pov showing glass coming over the lips and past the gums.

My favorite is when doctors investigate The Great Nippulini to find out how he lifts up to 70 lbs. using only his nipples. Be sure to set your Tivo’s and recorder for this Oct 8th, at 3am to capture the magic.

Still More Glass Fun Facts: Is Glass Solid or Liquid?

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We have often been told that old European cathedrals glazing show glass is still moving in a semi-solid state as the stained glass panels thicker at the bottom – right? Yes and no – but not for the change in the thickness of the glass.

Way back in 2008, this NY Times Science article delved into the nature of glass -

“…The (cathedral stained glass) tale contains a grain of truth about glass resembling a liquid, however. The arrangement of atoms and molecules in glass is indistinguishable from that of a liquid. But how can a liquid be as strikingly hard as glass?

“They’re the thickest and gooiest of liquids and the most disordered and structureless of rigid solids,” said Peter Harrowell, a professor of chemistry at the University of Sydney in Australia, speaking of glasses, which can be formed from different raw materials. “They sit right at this really profound sort of puzzle.”

“…scientists still disagree, with some vehemence, about the nature of glass.”

“Scientists are slowly accumulating more clues. A few years ago, experiments and computer simulations revealed something unexpected: as molten glass cools, the molecules do not slow down uniformly. Some areas jam rigid first while in other regions the molecules continue to skitter around in a liquid-like fashion. More strangely, the fast-moving regions look no different from the slow-moving ones.

Meanwhile, computer simulations have become sophisticated and large enough to provide additional insights, and yet more theories have been proffered to explain glasses.”

“The glass transition does not occur at a single, well-defined temperature; the slower the cooling, the lower the transition temperature. Even the definition of glass is arbitrary — basically a rate of flow so slow that it is too boring and time-consuming to watch. The final structure of the glass also depends on how slowly it has been cooled.”

The (very tech) article includes discussions what would happen withcooling at an infinitely slow rate- so not going to happen in this busy studio.

Click HERE to jump to the 2008 Kenneth Chang article in the NY Times.

Previous Glass Fun Facts postings:
Glass Fun Facts: Gaffer/Composer

More Glass Fun Facts: Bullseye Glass

Float Glass Fun Facts

Glass Fun Facts – Shattered Glass Predicts Weather

Why is Glass Transparent?